## 61977 Federal Register / Vol. 75, No. 194 / Thursday, October 7, 2010 / Rules and Regulations

agent). You are required to assure the product is airworthy before it is returned to service.

(3) Reporting Requirements: For any reporting requirement in this AD, under the provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq. ), the Office of Management and Budget (OMB) has approved the information collection requirements and has assigned OMB Control
Number 2120–0056.

Related Information

(j) Refer to MCAI European Aviation Safety Agency Airworthiness Directive 2009–0188, dated August 26, 2009; and Airbus Mandatory Service Bulletin A300–53–6161, Revision 02, dated October 16, 2009; for
related information.

Material Incorporated by Reference

(k) You must use Airbus Mandatory Service Bulletin A300–53–6161, Revision 02, including Appendix 01, dated October 16, 2009 to do the actions required by this AD, unless the AD specifies otherwise.

(1) The Director of the Federal Register approved the incorporation by reference of
this service information under 5 U.S.C. 552(a) and 1 CFR part 51.

(2) For service information identified in this AD, contact Airbus SAS—EAW (Airworthiness Office), 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France; telephone +33 5 61 93 36 96; fax +33 5 61 93 44 51; e-mail: account.airwortheas@airbus.com; Internet http://
www.airbus.com.

(3) You may review copies of the service information at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington. For information on the availability of this material at the FAA, call

425–227–1221.

(4) You may also review copies of the service information that is incorporated by
reference at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202–741–6030, or go

to: http://www.archives.gov/federal

_register/
code

_ of

_ federal

_regulations/ibr

_locations.
html.

Issued in Renton, Washington, on September 23, 2010.
Ali Bahrami, Manager, Transport Airplane Directorate, Aircraft Certification Service.

[FR Doc. 2010–25017 Filed 10–6–10; 8:45 am]

**BILLING CODE 4910–13–P** 

### DEPARTMENT OF TRANSPORTATION

**Federal Aviation Administration**

**14 CFR Part 39**

**[Docket No. FAA–2010–0552; Directorate Identifier 2009–NM–095–AD; Amendment**  **39–16464; AD 2010–21–04]**

**RIN 2120–AA64**



### Airworthiness Directives; The Boeing **Company Model 747–100, 747–200B, and 747–200F Series Airplanes** 

**AGENCY** 

### : Federal Aviation Administration (FAA), Department of Transportation (DOT).

**ACTION** 

### : Final rule.

**SUMMARY** 

### : The FAA is superseding two existing airworthiness directives (ADs), which apply to certain Model 747–100, 747–200B, and 747–200F series airplanes. The existing ADs currentlyrequire inspections to detect fatiguerelated skin cracks and corrosion of the skin panel lap joints in the fuselage upper lobe, and repair if necessary. One of the existing ADs, AD 94–12–09, also requires modification of certain lap joints and inspection of modified lap joints. The other AD, AD 90–15–06, requires repetitive detailed external visual inspections of the fuselage skin at the upper lobe skin lap joints for cracks and evidence of corrosion, and related investigative and corrective actions. This AD reduces the maximum interval of the post-modification inspections, and adds post-repair inspection requirements for certain airplanes. This AD results from reports of cracking on modified airplanes. We are issuing this AD to detect and correct fatigue cracking and corrosion in the fuselage upper lobe skin lap joints, which could lead to rapid decompression of the airplane and inability of the structure to carry fail-safe loads.

**DATES** 

### : This AD becomes effective November 12, 2010.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in the AD as of November 12, 2010.

**ADDRESSES** 

### : For service information identified in this AD, contact Boeing Commercial Airplanes, Attention: Data & Services Management, P.O. Box 3707, MC 2H–65, Seattle, Washington 98124– 2207; telephone 206–544–5000, extension 1; fax 206–766–5680; e-mail me.boecom@boeing.com; Internet https://www.myboeingfleet.com.
Examining the AD Docket

You may examine the AD docket on the Internet at http:// www.regulations.gov; or in person at the Docket Management Facility between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this AD, the regulatory evaluation, any comments received, and other information. The address for the Docket Office (telephone 800–647–5527) is the Document Management Facility, U.S. Department of Transportation, Docket Operations, M–30, West Building Ground Floor, Room W12–140, 1200 New Jersey Avenue, SE., Washington, DC 20590.

**FOR FURTHER INFORMATION CONTACT** 

### : Ivan Li, Aerospace Engineer, Airframe Branch, ANM–120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057–3356; telephone (425) 917–6437; fax (425) 917–6590.

**SUPPLEMENTARY INFORMATION** 

### :

Discussion

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an AD that supersedes AD 90–15–06, Amendment 39–6653 (55 FR 28600, July 12, 1990), and AD 94–12–09, Amendment 39–8937 (59 FR 30285, June 13, 1994). The existing ADs apply to certain Model 747–100, 747–200B, and 747–200F series airplanes. That NPRM was published in the Federal Register on June 22, 2010 (75 FR 35356). That NPRM proposed to continue to require inspections to detect fatigue-related skin cracks and corrosion of the skin panel lap joints in the fuselage upper lobe, and repair if necessary; modification of certain lap joints and inspection of modified lap joints; and repetitive detailed external visual inspections of the fuselage skin at the upper lobe skin lap joints for cracks and evidence of corrosion, and related investigative and corrective actions. That NPRM also proposed to reduce the maximum interval of the post-modification inspections, and adds post-repair inspection requirements for certain airplanes.

Comments

We provided the public the opportunity to participate in the development of this AD. We have considered the comment that has been received on the NPRM.
Request to Correct Typographical Error in Paragraph (l) of the NPRM

Boeing requests that we revise paragraph (l) of the NPRM to change the numeral ‘‘ 1 ’’ to the letter ‘‘ l ’’ to correctly identify the paragraph references.

We agree and have corrected the typographical error accordingly.


## 61978 Federal Register / Vol. 75, No. 194 / Thursday, October 7, 2010 / Rules and Regulations

Conclusion

We have carefully reviewed the available data, including the comment that has been received, and determined that air safety and the public interest require adopting the AD with the change described previously. We have determined that this change will neither increase the economic burden on any operator nor increase the scope of the
AD. Costs of Compliance There are about 23 airplanes of the affected design in the worldwide fleet. The following table provides the estimated costs for U.S. operators to comply with this AD.



### E STIMATED 

### C OSTS

Action Work hours Average labor rate per hour Parts Cost per airplane Number of U.S.- registered airplanes Fleet cost

Inspection (required by AD

94–12–09). 208 $85 $0 $17,680 per inspection cycle. 7 $123,760 per inspection cycle. Modification (required by AD

94–12–09). 8,160 85 0 $693,600 ............................. 7 $4,855,200.

Post-Modification Inspection

(required by AD 94–12– 09). 56 85 0 $4,760 per inspection cycle 7 $33,320 per inspection cycle.



### Authority for This Rulemaking

Title 49 of the United States Code specifies the FAA’s authority to issue rules on aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. Subtitle VII, Aviation Programs, describes in more detail the scope of the Agency’s authority.

We are issuing this rulemaking under the authority described in subtitle VII, part A, subpart III, section 44701,

‘‘ General requirements. ’’ Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking
action.
Regulatory Findings

We have determined that this AD will not have federalism implications under Executive Order 13132. This AD will not have a substantial direct effect on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government.

For the reasons discussed above, I certify that this AD:

(1) Is not a ‘‘ significant regulatory
action’’ under Executive Order 12866;

(2) Is not a ‘‘ significant rule ’’ under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and

(3) Will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act.

We prepared a regulatory evaluation of the estimated costs to comply with this AD and placed it in the AD docket.
See the **ADDRESSES** 

### section for a location to examine the regulatory evaluation.
List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.
Adoption of the Amendment

■ 

### Accordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows:

**PART 39—AIRWORTHINESS DIRECTIVES** 

■ 

### 1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. 106(g), 40113, 44701.

**§ 39.13 [Amended]**

■ 

### 2. The Federal Aviation Administration (FAA) amends § 39.13 by removing Amendment 39–6653 (55 FR 28600, July 12, 1990) and Amendment 39–8937 (59 FR 30285, June 13, 1994) and by adding the following new airworthiness directive (AD):
2010–21–04 The Boeing Company: Amendment 39–16464. Docket No. FAA–2010–0552; Directorate Identifier
2009–NM–095–AD.

Effective Date

(a) This AD becomes effective November
12, 2010.

Affected ADs

(b) This AD supersedes AD 90–15–06, Amendment 39–6653; and AD 94–12–09, Amendment 39–8937. Applicability (c) This AD applies to The Boeing Company Model 747–100, 747–200B, and 747–200F series airplanes, certificated in any category, as identified in Boeing Service Bulletin 747–53–2307, Revision 3, dated April 16, 2009.
Subject

(d) Air Transport Association (ATA) of America Code 53: Fuselage.

Unsafe Condition

(e) This AD results from reports of fatigue cracking on modified airplanes. The Federal Aviation Administration is issuing this AD to detect and correct fatigue cracking and corrosion in the fuselage upper lobe skin panel lap joints, which could lead to the rapid decompression of the airplane and the inability of the structure to carry fail-safe loads.
Compliance

(f) You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.
Restatement of Requirements of AD 94–12– 09, With Revised Service Information

Inspection

(g) Within 1,000 flight cycles after July 13, 1994 (the effective date of AD 94–12–09), and thereafter at the intervals specified in paragraphs (g)(1), (g)(2), and (g)(3) of this AD, perform inspections at the upper lobe skin panel lap joints in accordance with Boeing Service Bulletin 747–53–2307, Revision 2, dated October 14, 1993; or Revision 3, dated April 16, 2009. After the effective date of this AD, only Revision 3 may be used.

(1) Perform a detailed external visual inspection to detect cracks and evidence of corrosion (bulging skin between fasteners, blistered paint, dished fasteners, popped rivet heads, or loose fasteners) in accordance with Boeing Service Bulletin 747–53–2307, Revision 2, dated October 14, 1993; or Revision 3, dated April 16, 2009. After the effective date of this AD, only Revision 3 may


## 61979 Federal Register / Vol. 75, No. 194 / Thursday, October 7, 2010 / Rules and Regulations

be used. Repeat that inspection thereafter at intervals not to exceed 2,000 flight cycles until the modification required by paragraph (k) of this AD is accomplished.

(2) Perform a high frequency eddy current (HFEC) inspection to detect cracks in the skin at the upper row of fasteners of the skin panel lap joints forward of body station (BS) 1000 in accordance with Boeing Service Bulletin 747–53–2307, Revision 2, dated October 14, 1993; or Revision 3, dated April 16, 2009. After the effective date of this AD, only Revision 3 may be used. Repeat that inspection thereafter at intervals not to exceed 4,000 flight cycles until the modification required by paragraph (k) of this AD is accomplished.

(3) Perform a HFEC inspection to detect cracks in the skin at the upper row of fastener holes of the skin panel lap joints aft of BS 1480 to 2360 in accordance with Boeing Service Bulletin 747–53–2307, Revision 2, dated October 14, 1993; or Revision 3, dated April 16, 2009. After the effective date of this AD, only Revision 3 may be used.

Repeat that inspection thereafter at intervals not to exceed 6,000 flight cycles until the modification required by paragraph (k) of this AD is accomplished.

(h) If any crack is found during any inspection required by paragraph (g) or (l) of this AD, or if any corrosion is found for which material loss exceeds 10 percent of the material thickness, accomplish paragraphs (h)(1) and (h)(2) of this AD in accordance with Boeing Service Bulletin 747–53–2307, Revision 2, dated October 14, 1993; or Revision 3, dated April 16, 2009. After the effective date of this AD, only Revision 3 may be used.

(1) Prior to further flight, repair any crack or corrosion found, in accordance with Boeing Service Bulletin 747–53–2307, Revision 2, dated October 14, 1993; or Revision 3, dated April 16, 2009. After the effective date of this AD, only Revision 3 may be used.

(2) Within 18 months after accomplishing the repair, accomplish the ‘‘ full ’’ modification described in Boeing Service Bulletin 747–53– 2307, Revision 2, dated October 14, 1993; or Revision 3, dated April 16, 2009; for the remainder of any skin panel lap joint in which a crack is found, or in which corrosion is found that exceeds 10 percent of the material thickness, in accordance with Boeing Service Bulletin 747–53–2307, Revision 2, dated October 14, 1993; or Revision 3, dated April 16, 2009. After the effective date of this AD, only Revision 3 may be used.

(i) If no crack is found during any inspection required by paragraph (g) of this AD, but corrosion is found for which the material loss does not exceed 10 percent of the material thickness: Accomplish the actions specified in paragraphs (i)(1) and (i)(2) of this AD for the entire affected skin panel lap joint, in accordance with Boeing Service Bulletin 747–53–2307, Revision 2, dated October 14, 1993; or Revision 3, dated April 16, 2009. After the effective date of this AD, only Revision 3 may be used.

(1) Within 500 flight cycles after accomplishing the inspection during which the corrosion was found, and thereafter at intervals not to exceed 500 flight cycles until the ‘‘ full ’’ modification required by paragraph (i)(2) of this AD is accomplished: Perform a HFEC inspection to detect cracks of the corroded skin panel lap joint, in accordance with Boeing Service Bulletin 747–53–2307, Revision 2, dated October 14, 1993; or Revision 3, dated April 16, 2009. After the effective date of this AD, only Revision 3 may be used.

(2) Within 36 months after accomplishing the inspection during which the corrosion was found: Accomplish the ‘‘ full’’ modification, in accordance with Boeing Service Bulletin 747–53–2307, Revision 2, dated October 14, 1993; or Revision 3, dated April 16, 2009. After the effective date of this AD, only Revision 3 may be used.

(j) The inspections required by paragraph (g) of this AD shall be performed by removing the paint and using an approved chemical stripper; or by ensuring that each fastener head is clearly visible.

(k) Except as provided in paragraph (m) of this AD, prior to the accumulation of 20,000 total flight cycles, or within the next 1,000 flight cycles after July 13, 1994, whichever occurs later: Accomplish the modification described in Boeing Service Bulletin 747–53– 2307, Revision 2, dated October 14, 1993; or Revision 3, dated April 16, 2009; as a ‘‘ full’’ modification of the skin panel lap joints at the locations specified in paragraphs (k)(1) and (k)(2) of this AD, as applicable, in accordance with Boeing Service Bulletin 747–53–2307, Revision 2, dated October 14, 1993; or Revision 3, dated April 16, 2009. After the effective date of this AD, only Revision 3 may be used. Accomplishment of this modification terminates the repetitive inspection requirements of paragraph (g) of this AD.

(1) For airplane line numbers 001 through 058, inclusive: Modify the skin panel lap joints at Stringer 12 (left and right), station 520 to 1,000; and Stringer 19 (left and right),
station 520 to 740.

(2) For airplane line numbers 59 through 200, inclusive: Modify the skin panel lap joints at Stringer 12 (left and right), station 740 to 1,000; and Stringer 19 (left and right),
station 520 to 740.

(l) For all airplanes: Perform an external HFEC inspection to detect skin cracks of any modified skin panel lap joints at the times specified in paragraphs (l)(1), (l)(2), and (l)(3) of this AD, as applicable, in accordance with Boeing Service Bulletin 747–53–2307, Revision 2, dated October 14, 1993; or Revision 3, dated April 16, 2009. As of the effective date of this AD, only Revision 3 may be used. Repeat that inspection thereafter at intervals not to exceed 3,000 flight cycles, except as required by paragraph (n) of this
AD.

(1) For skin panel lap joints on which the

‘‘ full ’’ modification has been accomplished: Within 10,000 flight cycles after accomplishment of that modification.

(2) For skin panel lap joints on which the

‘‘ optional’’ (partial) modification has been accomplished: Within 7,000 flight cycles after accomplishment of that modification.

(3) For skin panel lap joints having deep countersink fasteners located at Section 42 on which the ‘‘ full’’ modification, as described in Boeing Service Bulletin 747–53– 2307, dated December 21, 1989, has been accomplished: Within 5,000 flight cycles after accomplishment of that modification.

(m) In lieu of the ‘‘ full’’ modification required by paragraph (k) of this AD, the

‘‘ optional’’ (partial) modification described in Boeing Service Bulletin 747–53–2307, Revision 2, dated October 14, 1993; or Revision 3, dated April 16, 2009; may be accomplished for skin panels that have an outer thickness of 0.090 inches or less, and that do not have any cracks, corrosion, or an existing structural repair on the skin panel lap joint. After the effective date of this AD, only Revision 3 may be used. The ‘‘ optional ’’ (partial) modification shall not be accomplished at deep countersink fastener locations. Accomplishment of this modification terminates the repetitive inspection requirements of paragraph (g) of this AD.
New Requirements of This AD
Post-Modification Inspection at Reduced Intervals

(n) Repeat the inspection required by paragraph (l) of this AD at the earlier of the times specified in paragraphs (n)(1) and (n)(2) of this AD. Thereafter, repeat the inspection at intervals not to exceed 1,000 flight cycles.

(1) Within 3,000 flight cycles after the last inspection done in accordance with paragraph (l) of this AD.

(2) Within 1,000 flight cycles after the last inspection done in accordance with paragraph (l) of this AD or 500 flight cycles after the effective date of this AD, whichever occurs later.
Post-Repair Inspection for External Doubler Repair

(o) For all airplanes: Do an internal surface HFEC inspection for cracking of the skin at any external doubler repairs greater than 40 inches in length (in the horizontal direction) within 1,000 flight cycles after the effective date of this AD, in accordance with the Accomplishment Instructions of Boeing Service Bulletin 747–53–2307, Revision 3, dated April 16, 2009. Thereafter, perform that inspection at intervals not to exceed 3,000 flight cycles.

(p) If any cracking is found during any inspection required by paragraph (o) of this AD, repair in accordance with the Accomplishment Instructions of Boeing Service Bulletin 747–53–2307, Revision 3, dated April 16, 2009.
Alternative Methods of Compliance (AMOCs)

(q)(1) The Manager, Seattle Aircraft Certification Office (ACO), FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. Send information to ATTN: Ivan Li, Aerospace Engineer, Airframe Branch, ANM–120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057–3356; telephone (425) 917–6437; fax (425) 917–6590. Or, e-mail information to 9-ANM-Seattle-ACOAMOC-Requests@faa.gov.

(2) To request a different method of compliance or a different compliance time


## 61980 Federal Register / Vol. 75, No. 194 / Thursday, October 7, 2010 / Rules and Regulations

for this AD, follow the procedures in 14 CFR 39.19. Before using any approved AMOC on any airplane to which the AMOC applies, notify your principal maintenance inspector (PMI) or principal avionics inspector (PAI), as appropriate, or lacking a principal inspector, your local Flight Standards District Office. The AMOC approval letter must specifically reference this AD.

(3) An AMOC that provides an acceptable level of safety may be used for any repair required by this AD, if it is approved by an Authorized Representative for the Boeing Commercial Airplanes Organization Designation Authorization who has been authorized by the Manager, Seattle ACO, to make those findings. For a repair method to be approved, the repair must meet the certification basis of the airplane, and the approval must specifically refer to this AD.

(4) AMOCs approved previously in accordance with AD 90–15–06, Amendment 39–6653; and AD 94–12–09, Amendment 39–8937; are approved as AMOCs for the corresponding provisions of this AD.

Material Incorporated by Reference

(r) You must use Boeing Service Bulletin 747–53–2307, Revision 3, dated April 16, 2009, to do the actions required by this AD, unless the AD specifies otherwise. If you accomplish the optional actions specified by this AD, you must use Boeing Service Bulletin 747–53–2307, Revision 3, dated April 16, 2009, to perform those actions, unless the AD specifies otherwise.

(1) The Director of the Federal Register approved the incorporation by reference of this service information under 5 U.S.C. 552(a) and 1 CFR part 51.

(2) For service information identified in this AD, contact Boeing Commercial Airplanes, Attention: Data & Services Management, P.O. Box 3707, MC 2H–65, Seattle, Washington 98124–2207; telephone 206–544–5000, extension 1; fax 206–766– 5680; e-mail me.boecom@boeing.com;
Internet https://www.myboeingfleet.com.

(3) You may review copies of the service information at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington. For information on the availability of this material at the FAA, call

425–227–1221.

(4) You may also review copies of the service information that is incorporated by reference at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202–741–6030, or go

to: http://www.archives.gov/federal

_register/ code

_ of

_ federal

_regulations/ ibr

_locations.html.
Issued in Renton, Washington, on September 23, 2010.
Ali Bahrami, Manager, Transport Airplane Directorate, Aircraft Certification Service.

[FR Doc. 2010–25019 Filed 10–6–10; 8:45 am]

**BILLING CODE 4910–13–P** 

### DEPARTMENT OF TRANSPORTATION

**Federal Aviation Administration**

**14 CFR Part 39**

**[Docket No. FAA–2010–0610; Directorate Identifier 2009–SW–47–AD; Amendment 39–**  **16455; AD 2010–20–20]**

**RIN 2120–AA64**



### Airworthiness Directives; Eurocopter **France Model SA–365N, SA–365N1, AS–365N2, AS–365N3, SA–366G1, EC**  **155B, EC155B1, SA–365C, SA–365C1, SA–365C2, SA–360C Helicopters** 

**AGENCY** 

### : Federal Aviation Administration, DOT.

**ACTION** 

### : Final rule.

**SUMMARY** 

### : This amendment supersedes an existing airworthiness directive (AD) for the specified Eurocopter France (Eurocopter) helicopters. That AD requires repetitively inspecting the main gearbox (MGB) planet gear carrier for a crack and replacing any MGB that has a cracked planet gear carrier before further flight. This action requires the same inspections required by the existing AD, but shortens the initial inspection interval. This AD is prompted by the discovery of another crack in a MGB planet gear carrier and additional analysis that indicates that the initial inspection interval must be shortened. The actions specified by this AD are intended to detect a crack in the web of the planet gear carrier, which could lead to a MGB seizure and subsequent loss of control of the helicopter.

**DATES** 

### : Effective November 12, 2010.

The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of November 12, 2010.

**ADDRESSES** 

### : You may examine the docket that contains this AD, any comments, and other information on the
Internet at http://www.regulations.gov, or at the Docket Operations office, West Building Ground Floor, Room W12–140, 1200 New Jersey Avenue, SE., Washington, DC.

You may get the service information identified in this AD from American Eurocopter Corporation, 2701 Forum Drive, Grand Prairie, Texas 75053–4005, telephone (972) 641–3460, fax (972)

641–3527.

Examining the Docket: You may examine the docket that contains this AD, any comments, and other information on the Internet at http:// www.regulations.gov, or at the Docket Operations office, West Building Ground Floor, Room W12–140, 1200 New Jersey Avenue, SE., Washington,
DC.

**FOR FURTHER INFORMATION CONTACT** 

### : Gary Roach, Aerospace Engineer, FAA, Regulations and Policy Group, 2601 Meacham Blvd., ASW–111, Fort Worth, Texas 76137; telephone: (817) 222– 5130; fax: 817–222–5961.

**SUPPLEMENTARY INFORMATION** 

### : A proposal to amend 14 CFR part 39 by superseding AD 2005–03–09, Amendment 39–13965 (70 FR 7382, February 14, 2005), for the specified Eurocopter France (Eurocopter) model helicopters was published in the Federal Register on June 28, 2010 (75 FR 36581). The action proposed to require shortening the initial inspection required by AD 2005–03–09 from 265 hours time-in-service (TIS) to 35 hours TIS and retaining the 50-hour TIS recurring inspections. That proposal was prompted by the finding of an additional crack in the MGB planet gear carrier of a Eurocopter Model EC 155 helicopter. That crack was caused by a progressive fatigue failure caused by scoring in the blend radius between the pin and the web. An additional analysis indicates that the initial inspection must be shortened. Therefore, this AD shortens the initial inspection from 265 hours time-in-service (TIS) to 35 hours TIS. The recurring 50 hour-TIS inspections would remain the same.

The European Aviation Safety Agency (EASA), which is the Technical Agent for France, has issued EASA Emergency Airworthiness Directive No. 2007– 0288–E, dated November 15, 2007. EASA states that cracks were discovered in the web of the MGB planet gear
carrier. ‘‘The two affected MGB units had been removed for overhaul/repair, subsequent to the detection of metal chips at the magnetic plugs. ’’ Investigation of the first case showed a failure of the head of a screw that secures the sun gear bearing. The screw head was caught by the planet gear/ fixed ring gear/sun gear drive train. The second case was discovered by the manufacturer and did not seem to be associated with any other failure. You may obtain further information by examining the MCAI and any related service information in the AD docket.

Related Service Information

Eurocopter France has issued the following Emergency Alert Service Bulletins:

• No. 05A007, Revision 2, for the Model EC155 helicopters;

• No. 05.00.48, Revision 3, for the Model AS365 helicopters;